


The Stand-in

by Itsallfine



Category: Sherlock (TV), Whiskey Tango Foxtrot (2016)
Genre: (a bit), Anal Sex, Blow Jobs, Crack, Dirty Talk, First Kiss, First Time, I Don't Know Anymore, Iain MacKelpie has a brief cameo, Iain MacKelpie's filthy language, Is this crack?, Jealous John, Love Confessions, M/M, Not truly a crossover fic, RL jealousy is shitty but jealous!john is a whole other thing, dicks doth touch within these pages, john is utter jealous trash, whiskey tango foxtrot
Language: English
Status: Completed
Published: 2017-04-21
Updated: 2017-04-21
Packaged: 2018-10-21 11:51:01
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,892
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10684725
Author URL: https://archiveofourown.org/users/Itsallfine/pseuds/Itsallfine
Summary: An old one-night stand of Sherlock’s shows up at Baker Street one day, a sassy Scottish fellow who bears more than a passing resemblance to John Watson. John goes into full jealous trash mode."Give me one good reason why I shouldn’t take him up on his offer.”Their gazes locked, both of them breathing hard through their anger.And something changed in John’s expression.“Because I’m making you a better one,” he said, low and firm.(You do NOT need to have seen WTF for this to be enjoyable, promise!)





	The Stand-in

**Author's Note:**

  * For [unknownsister](https://archiveofourown.org/users/unknownsister/gifts).
  * Inspired by [One Night in Karachi](https://archiveofourown.org/works/7393510) by [unknownsister](https://archiveofourown.org/users/unknownsister/pseuds/unknownsister). 



> I didn’t intend to write this, but I read [One Night in Karachi by unknownsister](http://archiveofourown.org/works/7393510), in which a pining Sherlock has a one-night stand with Iain MacKelpie (Martin Freeman’s character from WTF), and immediately messaged the author on twitter to beg for permission to write this. It took over my brain. It was SCREAMING for Jealous!John. You don’t have to have read that fic for this one to make sense, but you should anyway because it’s great.
> 
> You absolutely do NOT need to have seen WTF to understand this fic. It just provides the character of Iain, who makes a brief appearance and is completely self-explanatory. In fact, the movie is pretty horrible racist garbage, but you can see all of Martin’s scenes cut together on youtube. Do yourself a favor. It’s worth it.
> 
> I'm real rusty at writing explicit content (it's been almost a year and a half, whaaaat?), so please bear with me while I shake out the cobwebs.

 

Sherlock Holmes was languid and content from his post-case shower and fully absorbed in the comforts of 221B. His shirt sleeves were rolled up to his elbows, his feet were bare under the cuffs of his trousers, and a hot cup of perfect tea sat as his elbow as he slouched in his desk chair and scrolled through his inbox, lazily solving a few cases with quick emails.

A firm knock came at the door downstairs, then Mrs. Hudson’s cooing speech. Ah. John’s tread on the stairs, steady and confident, never managing to miss any of the creaky parts but also not caring. Sherlock smiled faintly.

Then he sat bolt upright.

John was already in the room. Lounging in his chair. John wouldn’t knock at the front door.

It couldn’t be John on the stairs.

“Client?” John asked, glancing over his newspaper at Sherlock. “Expecting anyone?”

Sherlock shook his head faintly.

 _It can’t be_.

He lurched to his feet and was halfway across the sitting room in two long strides when a handsome face with a scruffy gingerish beard poked through the open doorway, followed by a body wrapped in scottish wool and a Celtic FC scarf. The man’s eyes sparked as he gave Sherlock an obvious once-over, then tossed him a roguish grin and stepped fully into the flat.

“Well, hello there, gorgeous. Long time no see.”

Sherlock froze, his eyes absorbing every detail as a door in his mind palace flew open, spilling vivid memories of _come on, you gorgeous creature_ and _yes, yes, that’s it_ and _mark me up, I want to see it,_ all purred in that thick Scottish accent.

“Iain.” He blinked.

Iain took another step into the room. “Would have been by sooner, but you never answered my fucking texts, you cunt.”

“I was… in a bad place at the time,” Sherlock said, hesitant. “And on a case. And I got shot, a bit.”

“Well, I suppose I can forgive you that, then.”

John stood from his chair and puffed his chest out, his eyes hard and wary.

“Who’s this?”

Iain pursed his lips to hold in a laugh, and Sherlock winced.

“John Watson, Iain MacKelpie,” he said, gesturing from one to the other in introduction. “War photographer and photojournalist. In Afghanistan and the surrounding region for the last ten years, with occasional forays elsewhere. Promiscuous. Functioning alcoholic. Bit of an arse.”

“You forgot devastatingly handsome and incredible lover. I’m hurt,” Iain said, staggering back with a hand clutched over his heart.

Sherlock flushed and tapped the fingers of his right hand against his thigh as the ball of tension that was John Watson moved closer. Iain raised an eyebrow at him.

“Huh. It’s like looking in a bleeding mirror, it is,” Iain said, looking John over from head to toe. “A very boring, stuffy mirror, but you were right, Sherlock, I do certainly see the resemblance.”

John bristled, but Iain charged on.

“Forgive me, lads, I know it's rude to show up at the flat of your old one night stand unannounced—”

John coughed violently.

“—but I found myself unbearably curious. And you did leave me your address and phone number, after all. Really, you invited me. And you certainly know how to leave an impression, Sherlock Holmes."

Sherlock chuckled, inexplicably charmed just like before, the easy camaraderie falling back into place.

“You could have called first.”

Iain smirked. “Ahh, but that would have spoiled the surprise.”

Sherlock couldn't help it. His mouth twisted into a smile without his permission, though he fought it as best he could, feeling his cheeks grow warmer still. Iain’s grin widened at the blush and advanced another step, right into Sherlock’s space.

“Thought you could show me around London for the night, take me out on the town. And in a country where sucking cock isn’t illegal, too, what a luxury! What do you say, posh boy?”

Sherlock’s lips parted at the overwhelming sense memory of that scruffy almost-beard prickling at his chin, his cheek, his throat—god, he was tempted. He hadn’t been with anyone since that night in Karachi, and with John sharing his space again the need was a constant simmer just under his skin, hot and yearning.

But _John_.

If he ever wanted a chance with John…

John, who was practically growling beside him, pacing and clenching his fists, doing the sniff thing that meant his temper was barely in check.

“I can’t,” Sherlock said after a moment, regretful. “Sorry.”

“Nah, I understand,” Iain said with a shrug, cutting his eyes over to John. “Can’t blame a bloke for trying.”

And, against all logic and sanity, Iain held out a hand to John for a shake. He pasted on what passed for a polite smile, still two-thirds sardonic at the best of times, and shook his head when John accepted his hand.

“I know we’ve only just met, John, but I hope you don’t mind me saying,” he began, shaking their hands once, firm, “but you're a bloody idiot, you utter tosser. You have no idea what you have."

Sherlock felt all the color drain from his face as John’s mouth pressed into a hard line.

"Iain—"

Iain held up his hands in surrender, but he smirked, the damage already done. He flipped out his wallet and withdrew a business card from between the crammed-in condoms, then tucked it into Sherlock’s back trouser pocket.

"Call me if you change your mind, beautiful," Iain said. Then he leaned up and pressed his lips to Sherlock’s, a brief kiss that lingered, then lingered some more, edging quickly into something else altogether until a pointed clearing of John’s throat cut them off. When he leaned away, Iain let out a breath and shook his head ruefully.

"That mouth haunts my dreams," Iain said, and tapped two fingers over the business card in Sherlock’s pocket. He stepped back, shoved his hands in his pockets and raised his eyebrows cheekily at John, then tossed a quick wink at Sherlock on his way out the door. His retreating footsteps seemed to carry all the air in the room with him.

It was deadly quiet.

“You slept with him.”

John’s voice was low and dangerous beside him. Sherlock kept his eyes fixed on the door, didn’t turn around.

“It was over a year ago, John—”

“You _slept_ with that wanker,” John cut in, louder. “When were you even in Afghanistan?”

Sherlock whirled to face him. “I took a short case there while you were on your sex holiday with Mary, not that _any_ of this is your business in the slightest.”

John gave a humorless laugh, walked a few paces away, then returned.

“I thought you didn’t—I thought—you said _not your area_ —”

Sherlock huffed. “I said _women_ weren’t my area. Iain is most decidedly _not_ a woman.”

“You’re gay, then,” John said, suddenly intent. He licked his lips, pinned Sherlock with an intense stare.

Sherlock bit the inside of his bottom lip and glanced away.

“Obviously.”

John nodded. “Not married to your work anymore?”

Sherlock winced. No good way around it.

“I haven’t been for a very long time, John.”

The echoing silence was too much. Sherlock slipped Iain’s card from his pocket and turned it over in his hand a few times, then strode over to his desk to get his phone. New contact, Iain MacKelpie, new messa—

“What are you doing?” John demanded.

Sherlock rolled his eyes. “I’m texting Iain.”

“You’re—Sherlock, why on _earth_ would you want to go out with a wanker like that? Why _him_?”

“I see no reason not to. He was a perfectly adequate lover, and lacking any other options—”

“You have options, Sherlock.”

Sherlock dropped the phone back to the desk and spun to face John.

“Who, John? Where? And why should I bother when I have someone right here—” he held up the business card, “—who has already offered? We had fun. It was fine. He’s a bit of a bastard, but so am I, as you’ve told me on numerous occasions. I _liked_ him. Give me one good reason why I shouldn’t take him up on his offer.”

Their gazes locked, both of them breathing hard through their anger.

And something changed in John’s expression.

“Because I’m making you a better one,” he said, low and firm. He took a step closer to Sherlock.

Sherlock blinked.

“You—”

“I’m making you a better offer,” John said, stepping closer still. He plucked the business card from Sherlock’s fingers and tossed it on the desk, then took Sherlock’s hand in his.

“Let _me_ take you out tonight. Let _me_ be the one you take to bed. And I promise, Sherlock,” he growled, “whatever he did for you, I’ll do better.”

Sherlock’s brain went into overdrive. Deduce, quickly: Pupils dilated. Racing pulse. Physical proximity. Steady hands.

 _John_.

“You mean… you…”

John laughed, but the sound was brittle. “Here I am, in love with you for years, thinking you just don’t do sex, or love, then you run off to Afghanistan and have it off with a bloke like that. _God_ , Sherlock. And he looks _just like me_. What am I supposed to think?”

John swallowed hard, and Sherlock watched the motion of his throat, barely breathing.

“Please tell me I’m not reading this wrong,” John begged.

The hand around Sherlock’s tightened, and his heart ached, beat hard, sent a pulse of fire through his veins to pool low in his stomach. He felt like a live wire, like a gas main waiting for a spark, and John—

John licked his lips again and stared straight into his eyes, unflinching. Braced to accept his fate.

“How about we skip the going out part,” Sherlock said, shifting closer until he could feel the heat of John all along his body, “and go straight to bed.”

John let out a harsh breath and leaned up to nuzzle their noses together, his eyes closed, his watery smile the sweetest thing Sherlock had ever seen.

“God, yeah, you’re a genius,” John breathed over Sherlock’s lips.

Then he sealed their mouths together, and Sherlock groaned high and desperate, every nerve in his body coming fully alive in a riot of sensation. He stumbled back until his legs hit the the desk and slid down, propping his arse on the edge and dragging John forward into the vee of his legs. John’s lips were hot and insistent against his, a firm press that came again and again, punctuated by ragged gasps that inevitably turned to inappropriate laughter instead. They pressed their foreheads together, and Sherlock lifted both hands to cup the back of John’s head, threading his fingers through gray-blonde hair.

“Say it again. What you said earlier. Tell me again,” Sherlock asked, swaying in for another soft kiss. John hummed into it, then pulled back just far enough to meet Sherlock’s gaze.

“I love you,” he whispered, and leaned in to press the words into his cheek, his earlobe, his hair. “I love you, Sherlock, so much, for so long.”

Sherlock tightened his hold around John’s waist until they were flush together, until Sherlock could feel John’s heart beating against his. He took a breath, squeezed his eyes shut, and confessed into the curve of John’s neck: “I love you too. Always have.”

His voice was hoarse, strained, but god, the words were out for the first time in his life and he felt _light._ A weight off his soul, words shared rather than hidden away, and it was the start of a chain reaction he couldn’t control.

“That was why, John,” he said, and sealed their mouths together again, hard, then broke away to babble, “That was the only reason, you were married, I’d just let you go and he looked so much like you—”

John cut him off with another kiss, harder and more desperate. “I’m so sorry, Sherlock, if I had known I would never—”

Sherlock hauled John against him and slanted their mouths together, tracing his tongue along John’s bottom lip so he could dip inside, slide his tongue hot and demanding against John’s until they were both hard and gasping. John ground against him and let out a stuttering moan at the feel of their cocks moving together for the first time.

“Bed,” he demanded, and Sherlock groaned his agreement. John scooped both hands under Sherlock’s arse cheeks and hauled him up off the edge of the desk, then went in for another bruising kiss. Sherlock buried one hand in John’s hair and wrapped the other low around his back to guide their slow shuffle toward the bedroom.

As soon as they made it inside, Sherlock fell back onto the bed and propped himself up on his elbows, his hard cock obscenely obvious in his tented trousers. He watched John’s eyes go dark, watched the slow slide of his smile from sweet into dirty, and he threw his head back in submission as John climbed onto the bed, on top of him, hands at the buttons of Sherlock’s shirt.

“What did you do with him, Sherlock?” John demanded, breathing hot over Sherlock’s pulse point, his hands wandering over Sherlock’s chest. He thumbed a tight nipple through the thin fabric of Sherlock’s shirt. “Tell me.”

Sherlock shivered hard, his hips bucking uncontrollably with each pass of John’s thumb. “I… he… he wanted my mouth.”

“I can’t blame him,” John said, leaving Sherlock’s chest alone just long enough to trace a thumb over his bottom lip instead. “This clever mouth of yours is a daily torment. So you sucked him off, yeah?”

A biting kiss into the side of Sherlock’s neck drove a cry from his throat, and he grabbed John’s arse with both hands, thrust up hard.

“Ah! Yeah… yes… He said he wanted the best blowjob of his life and I gave it to him.”

“I don’t doubt it. And what did he give you?”

Sherlock yanked at John’s jumper and vest until he had delicious bare chest above him, then dropped his hands to wrestle with John’s trousers.

“I rubbed off against him, made a mess of him, while he touched me and… said things.”

John scoffed and dragged a hand up Sherlock’s clothed erection. Sherlock bit his lip and closed his eyes against the strength of the sensation, struggling with John’s zipper.

“Only a rub off? That’s all he gave you, after the best blowjob of his life? Shameful. What a waste.”

Sherlock huffed a laugh and finally won his battle with John’s fly, slipping his hand inside to cup around John’s hard cock. Above him, John sucked in a hard breath and rolled his hips, and Sherlock grinned, leaning up to murmur in his ear.

“I was too far gone for anything else. I was—Ah! I was picturing you—when I—he looks like—”

“Yeah, that’s right. While you had your lips wrapped around his prick, you were thinking of _me,”_ John growled. “I’ll do so much better for you, Sherlock. I’ll do anything you want, I’ll make it so good.”

“You want my mouth, too,” Sherlock gasped as John tongued at his nipple and worked his hand over him. He grabbed John and rolled them over, slid down his body with harsh, open-mouthed kisses for each of his hipbones. “You want to erase the taste of him, the feel of him. Make me completely yours.”

Sherlock pulled the waistband of John’s boxer briefs down and licked the bead of moisture from the tip of John’s cock with one quick flick of his tongue. A ragged moan tore from their throats in unison, and Sherlock dove back for more, the burst of John’s taste on his tongue a new and deadly addiction. He tongued at John’s bollocks, dragged a firm stripe up the underside of his cock, then plunged down to take the whole thing, pressing his nose into John’s groin to absorb his scent. Sherlock swallowed once around the head of John’s cock, the pulled back with an achingly slow drag, and set the pace with long pulls and leisurely traces over the slit, under the head, every spot that made John gasp and clutch the sheets.

“Do you want to come like this?” Sherlock asked, pulling off just long enough to suck a bruise into the inside of John’s thigh. “In my mouth while I swallow you down?”

John cried out as Sherlock took his cock in again, his fingers tangling in dark curls and pulling a rumbling groan from Sherlock’s throat.

“Yes,” John said, then shook his head, pulled at Sherlock’s hair to slow him down. “No, I mean. No, I want to get my hands on you first. My mouth, my cock, god, Sherlock, I want to _wreck_ you.”

Sherlock pulled off with a shudder at those words, and John hauled him further up the bed, arranged them so Sherlock’s dark hair nestled against the pillows. He looked up at John, his heart in his throat, and drew John’s full weight down on top of him, wound him up in arms and legs and ground their hips together with his face buried in John’s neck. John worked his hands under Sherlock’s arse and pulled them still closer together, pulled Sherlock’s cheeks apart in a way that made Sherlock throw his head back at the wanton exposure.

“Did you let him fuck you?” John demanded, pulling back just enough to shift his spit-slick cock between Sherlock’s legs. Sherlock jerked hard, a thrill of pleasure blooming at the base of his spine.

“No,” Sherlock gasped, shifting with restless need as the head of John’s prick dragged between his arse cheeks. John smirked.

“Are you gonna let _me_ fuck you?”

“God, yes, please,” Sherlock begged, his desperation spilling over. He hooked a finger into the bedside drawer and grasped blindly for the lube, then pressed it into John’s hand. “If you can shut up long enough to get your prick in me then you can fuck me all night if you want to, just _get on with it_.”

John laughed and scooped a hand under Sherlock’s hips so he could shove a pillow under, then lay down between Sherlock’s legs. Sherlock squeezed his eyes shut and arched his back as John’s tongue explored _everywhere_ , teasing the slit, laving over his balls, the crease of his thigh, pushing hard over his perineum. He writhed under John’s mouth, clutching his fingers in his own hair, and when John’s slick finger finally circled his hole and pressed in, it drove the air from his lungs, and he bore down against it with a needy moan.

“God, that’s gorgeous, you’re _gorgeous_ , Sherlock,” John murmured into the skin of his thighs, thrusting and twisting with first one, then two fingers, and Sherlock was inside-out, flying apart from the sparking pleasure in his gut. Another finger, and he whined, high and long, as he drove himself down, fucking himself on John’s hand.

“John, now, please, _hurry up_ ,” he demanded, then let out a distressed groan when John removed his fingers.

“Condom in the drawer?” John asked, leaning over to fish one out. Sherlock locked his legs around John’s waist and held him in place.

“I’m clean. Tested. You?”

John nodded. “You sure you’re ready for that?”

Sherlock raised an eyebrow. “John.”

John smiled, bent down to frame Sherlock’s face with his thumbs and press a sweet kiss on his lips. His eyes were soft and bright, such a deep blue when viewed so close up, and the mischievous crinkle at their corners stoked the fire in Sherlock’s belly. He lifted his hips and dragged himself over John’s slick cock with an impatient groan.

“Joooohn, _please_.”

“All right, all right, love,” John said, gentling him with soft brushes of hands over shoulders and chest. He hooked one of Sherlock’s legs over his good shoulder and lined himself up, then glanced up and caught Sherlock’s gaze as he nudged himself just barely inside with a roll of his hips. Sherlock shivered at the initial push, his cock twitching at the wave of need it sent to the tips of his fingers and toes, then groaned in frustration when John only circled his hips, barely rocking in and out, shallow, _maddening._

“Damn it, John, I swear if you don—GOD!” Sherlock choked on the rest of the sentence as John finally thrust in earnest, sinking fully into him in three long, slow strokes, groaning through his cocky smirk. Sherlock melted back into the soft duvet and pushed back against John, taking him deep, his mouth open and panting. He felt… open, flayed, like he’d broken apart and every bit of his love and pleasure pooled around him for John to see. Sherlock reached up, pulled John close and just breathed, just let John fill him up and ground him and utterly _destroy_ him.

“Ah, god, _fuck_ , Sherlock,” John gasped, changing his angle and sinking in again and again, sending a flurry of sparks through Sherlock with every drag of his cockhead over sensitive prostate, and Sherlock whined, rode back into him, needing more, _more_.

“Do it, Sherlock, fuck, come on,” John said, and let go of Sherlock’s hip to take his cock instead. That simple touch, and Sherlock was already there, riding right on the edge, so close, pulled taut and shivering and—

“John, _John_ , ah—!”

His pleasure broke over him, and he spilled and fucked back against John’s cock, meeting him thrust for thrust until John flooded his body with warmth, his wrecked moan stored in Sherlock’s mind palace to be put on permanent repeat. Sherlock clutched at John’s shoulders and back until he could drag him down, pressed together all along their fronts, pouring their ragged groans into each others mouths. His legs, still wrapped around John’s waist, tightened around him to hold John inside. John’s thrusts slowed, became leisurely, until oversensitive shivers drove him to finally pull out with a kiss of apology to compensate for the sudden emptiness. They collapsed side by side on the bed, curled in on each other in a tangle of limbs, hearts racing in the aftermath. Sherlock ran his hands over every inch of John’s back, arms, and shoulders he could reach, humming his satisfaction into John’s silver-gold hair.   

“God,” John said, breathless.

“Yes,” Sherlock agreed.

They broke into ridiculous giggles again, clutching each other even tighter. Sherlock rubbed his cheek against John’s and let his purely contented smile go unchecked, reveling in the marvel that was John Watson in his bed, sated and happy and _his_.

John nipped at the corner of Sherlock’s jaw and tugged gently at his hair. “I cannot _believe_ you went out and slept with a man who looked exactly like me. In _Afghanistan._ ”

Sherlock shrugged as best he could with all his spindly limbs wrapped up in John. “Yes, well, can you truly blame me?”

“Not at all,” John said.

But there was something off in his voice, and the deductions lined up with hardly a conscious thought.

“John,” he said, surprised, as the pieces fell together. “You did it, too.”

John smiled, a bit sheepish.

“Yeah, okay, you caught me. While you were… gone, there was this American bloke, showed up on the street one day. Stephen. A doctor, bit scruffy, but looked _just_ like you, right down to the cheekbones…”

 

 

THE END

  


**Author's Note:**

> Okay, I was SO tempted to do one of two really dirty things with this: 
> 
> 1) make it so JOHN once had a one night stand with Iain as well (they were both in Afghanistan at the same time!)  
> and/or  
> 2) Threesome.
> 
> So like. If either of those ideas appeal to y’all, you should write them. Please. And send me the link.
> 
> Also, John’s one night stand he references at the end is Ben C’s character Doctor Strange, if that wasn’t obvious enough, and the beautiful [kimbiablue](http://kimbiablue.tumblr.com) wrote a John/Stephen companion fic to this one inspired by my cracky ending. Except hers is actually all sweet and pining and a little angsty and HOT. [CLICK HERE AND GO READ IT RIGHT NOW](http://www.archiveofourown.org/works/10685643).
> 
> Soooo, if you still want to be around me after Alla That, you can follow me on tumblr for fic updates and general shenanigans at [librarylock](http://librarylock.tumblr.com)


End file.
